oop-macro 0.0.2

Macros for the oop package
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63

use proc_macro::TokenStream;
use proc_macro2::TokenTree;
use quote::quote;
use syn::{parse_macro_input, ItemStruct, parse::Parse, Type};

struct ExtendArgs {
	target: Box<Type>,
	field_name: TokenTree,
}

impl Parse for ExtendArgs {
    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
        let target = input.parse()?;
		input.parse::<syn::Token![,]>()?;
		let field_name = input.parse()?;
		Ok(
			Self {
				target,
				field_name,
			}
		)
    }
}

#[proc_macro_attribute]
pub fn extend(attr: TokenStream, mut item: TokenStream) -> TokenStream {
	let item2 = item.clone();
	let input = parse_macro_input!(item2 as ItemStruct);
	let args = parse_macro_input!(attr as ExtendArgs);
	
	let struct_name = input.ident;
	let target = args.target;
	let field_name = args.field_name;
	item.extend::<TokenStream>(
		quote! {
			impl ::core::ops::Deref for #struct_name {
				type Target = #target;
				
				fn deref(&self) -> &Self::Target {
					&self.#field_name
				}
			}
			
			impl ::core::ops::DerefMut for #struct_name {
				fn deref_mut(&mut self) -> &mut Self::Target {
					&mut self.#field_name
				}
			}
			
			impl #struct_name {
				pub fn _super(&self) -> &#target {
					<Self as ::core::ops::Deref>::deref(self)
				}
				
				pub fn _super_mut(&mut self) -> &mut #target {
					<Self as ::core::ops::DerefMut>::deref_mut(self)
				}
			}
		}.into()
	);
	
	item
}